1. Field of the Invention
The present invention is in the field of window devices and is directed more particularly to an improved window assembly including a fixed frame member within which an operating sash is pivotally mounted, the device being characterized by a high degree of thermal isolation, a highly pleasing aesthetic appearance, and the ability readily to remove and replace broken glass without the necessity for disassembling the frame.
2. The Prior Art
Modern building constructions, and particularly high rise building constructions, employ in a large majority of instances exterior portions comprised predominantly of glass. Typically, the building may include a mixture of fixed glazing and operating sashes.
In accordance with present architectural thinking, it is considered highly desirable that the sight line or thickness of metal surrounding the glass members be minimized for aesthetic and economic reasons and to minimize heat losses through the frame. Additionally, the window construction incorporating the operating sash in the closed position must provide a high degree of thermal isolation to avoid heat loss in the winter or admission of heat to air-conditioned premises in the summer. It is, moreover, highly desirable, in the event of glass breakage, that the glass lites be replaceable, preferaby without disassembly of the operating sash structure.
It is a further obvious desideratum that the window construction be as inexpensive as is feasible consistent with safety and aesthetics.
Numerous window constructions attempting to realize one or more of the above mentioned desirable factors have been created, which window structures, in varying degrees, achieve the desired ends.
Certain of the window structures, such as illustrated by way of example, in U.S. Pat. No. 3289,377--Hetman--provide relatively effective thermal breaks and, consequently, low heat loss. Other of the windows, as exemplified by U.S. Pat. Nos. 4,132,035, Frambach and others attempt to provide relatively narrow sight lines and, in addition, relatively efficient thermal isolation.
Various sealing materials have been employed as a means for isolating the glazing from the glazing-adjacent surfaces. Additionally, numerous glazing systems have been suggested, which systems employ, inter alia, Neoprene, vinyl and/or silicone materials. By way of example, reference may be made to a brochure published by General Electric Corporation and entitled "Silicone Construction Sealants in Structural Glazing Systems" (Silicone sealant design guide #4.)
In all of the window structures heretofore known wherein an operating sash is carried within a metal or like frame or perimeter member mounted to the structural components of the building, no single unit has been created which incorporates all of the aforesaid desiderata.